EV Fires

EV Fires

Subject: Science & Tech

Section: MSc

Context- The growing EV mishaps are worrying. The Centre should act fast to establish battery safety standards.

Concept-

• Sales of EV two ­wheel­ers have risen five times (463 per cent) to 2.31 lakh in 2021­22.
• This is the fastest growing segment, ac­counting for over half of total EV sales.

Why only EV Two wheelers catching fire:

• That only two wheeler batteries are catching fire, and not those of cars or three wheelers, is not surprising because of two reasons —
  • one, there are more two­ wheelers on the roads and,
  • two, unlike the other segments, the two wheeler market is highly price sensitive, which has apparently driven the manu­facturers to cut costs by compromising on safety.

EV Batteries:

• There is little doubt that the main culprit is battery chemistry.
• Lithium Ion batteries are of many makes, depending upon which other ele­ments lithium has been married to.
• The most commonly used chemistry in two wheelers is nickel manganese cobalt, or NMC, which while being the best in terms of performance and costs, are the most inflammable.
• Not surprisingly, most two wheeler makers have procured NMC batter­ies from China. These are not suited to India’s hot climate.
• Other Li Ion chemistries, such as lithium ferro phosphate (LFP) and lithium titanate oxide (LTO) are costly, but safe.

What can be done:

• NMC could be used with safety features.
• There is plenty on the technology table — such as
  • dual fuse for each cell which will automatically cut off if either the temperature or current exceeds a limit,
  • active thermal manage­ment to cool down the battery,
  • a temperature in­dicator with a buzzer to warn the rider and an emergency switch­off system.
• The Centre should incentivise the use of solid state batteries, which have no inflam­mable, liquid electrolytes such as those based on abundant, indi­genous materials such as sodium, zinc and alu­minum.